Ionic compounds with delocalized anionic charge, and their use as ion conducting components or as catalysts

ABSTRACT

The invention relates to an ionic compound corresponding to the formula [R 1 X 1 (Z 1 )—Q − —X 2 (Z 2 )—R 2 ] m  M m+  in which M m+  is a cation of valency m, each of the groups X i  is S═Z 3 , S═Z 4 , P—R 3  or P—R 4 ; Q is N, CR 5 , CCN or CSO 2 R 5 , each of the groups Z i  is ═O, ═NC≡N, ═C(C≡N) 2 , ═NS (═Z) 2 R 6  or ═C[S(═Z) 2 R 6 ] 2 , each of the groups R i , is Y, YO—, YS—, Y 2 N— or F, Y represents a monovalent organic radical or alternatively Y is a repeating unit of a polymeric frame. 
     The compounds are useful for producing ion conducting materials or electrolytes, as catalysts and for doping polymers.

This application is a divisional of application Ser. No. 09/931,076,filed Aug. 17, 2001, now U.S. Pat. No. 6,548,567, which is a divisionalof application Ser. No. 09/269,264 filed Mar. 25, 1999, now U.S. Pat.No. 6,340,716, which is a 371 national stage application ofPCT/FR98/01663, filed Jul. 27, 1998.

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

The present invention relates to ionic compounds comprising a highlydelocalized anionic charge, to a process for their preparation and totheir uses.

It is well known that the salts of strong acids such as HClO₄, HBF₄,HPF₆ and HR_(F)SO₃ (R_(F)=perfluororadical) have properties in the fieldof electrochemistry and catalysis, but these properties are limited. The“superacids” obtained by adding a Lewis acid such as SbF₅ to theabovementioned compounds are moreover known. However, these compoundsare not stable other than in protonated form and in non-solvating mediasuch as aliphatic hydrocarbons. The salts are unstable in the usualpolar solvents.

Perfluorosulfonimide derivatives H[R_(F)SO₂NSO₂R_(F)](R_(F)=perfluoroalkyl) have been studied since quite recently. They haveadvantageous stability properties in protonated form or in the form ofsalts and are used as solutes in electrochemistry and as catalysts.However, it is not possible to give these salts all of the propertiesrequired for all the applications, in particular in terms of acidity,dissociation or solubility, since the use of compounds containingperfluoro chains of several carbons only slightly increases the acidityor the dissociation of the salts, when compared with the simplestcompound R_(F)=CF₃, and induces rigidity in the molecule to thedetriment of the conductivity properties. Long fluoro chains are bothhydrophobic and oleophobic and do not allow any appreciable increase inthe solubility in organic media. Replacement of the groups R_(F) in thesimple imides with non-perfluoro or only partially fluorinated groupsreduces the acidity and the solubility substantially.

The aim of the present invention is to provide novel ionic compoundsderived from perfluorosulfonimides in which the delocalization of theanionic charge is improved, thus resulting in markedly better acidityand dissociation than those of the known compounds, while at the sametime retaining good stability.

SUMMARY OF THE INVENTION

Accordingly, a subject of the present invention is ionic compounds,their uses and a process for preparing them.

One compound according to the invention is an ionic compoundcorresponding to the formula

in which:

-   -   M^(m+) is a proton or a metal cation having the valency m,        chosen from ions of alkali metals, of alkaline-earth metals, of        transition metals or of rare-earth metals, or an organic onium        cation or an organometallic cation, 1≦m≦3;    -   X¹ and X², denoted below by X^(i), represent, independently of        each other, S═Z³, S═Z⁴, P—R³ or P—R⁴;    -   Q represents N, CR⁵, CCN or CSO₂R⁵;    -   Z¹, Z², Z³ and Z⁴, denoted below by Z^(i), represent,        independently of each other, ═O, ═NC≡N, ═C(C≡N)₂, ═NS(═Z)₂R⁶ or        ═C[S(═Z)₂R⁶]₂, Z having the same meaning as Z^(i), it being        understood that, in a segment —X¹—Q—X²—, not more than 3 groups        Z^(i) represent ═O;    -   R¹, R², R³, R⁴, R⁵ and R⁶, denoted below by R^(i), represent,        independently of each other, Y, YO—, YS—, Y₂N— or F;    -   Y represents a monovalent organic radical, preferably containing        from 1 to 16 carbon atoms, chosen from alkyl, alkenyl, oxaalkyl,        oxaalkenyl, azaalkyl, azaalkenyl, aryl, alkylaryl or        perfluoroalkyl radicals, or from the radicals obtained from the        abovementioned radicals by substitution, in the chains and/or        the aromatic part, with hetero atoms such as halogens, oxygen,        nitrogen, sulfur or phosphorus; it being understood that sulfur        or phosphorus are present, they can optionally be linked to        substituted oxygen or nitrogen atoms, or alternatively Y is a        repeating unit of a polymeric frame.

When M^(m+) is a metal cation, it can be an alkali metal (in particularLi⁺ and K⁺), an alkaline-earth metal (in particular Mg⁺⁺, Ca⁺⁺ or Ba⁺⁺),a transition metal (in particular Cu⁺⁺, Zn⁺⁺ or Fe⁺⁺) or a rare-earthmetal (in particular Re⁺⁺⁺).

When M^(m+) is an onium cation, it can be chosen from ammonium ions[N(Y^(j))₄]⁺, amidinium ions RC[N(Y^(j))₂]₂ ⁺, guanidinium ionsC[N(Y^(j))₂]₃+, pyridinium ions [C₅N(Y^(j))₆]⁺, imidpazolium ionsC₃N₂(Y^(j))₅ ⁺, imidazolinium ions C₃N₂(Y^(j))₇ ⁺, triazolium ionsC₂N₃(Y^(j))₄ ⁺, carbonium ions C₅(Y^(j))₅C⁺, NO⁺ (nitrosyl) or NO₂ ⁺ions, sulfonium ions [S(Y^(j))₃]⁺, phosphonium ions [P(Y^(j))₄]⁺ andiodonium ions [I(Y^(j))₂]⁺. In the various abovementioned onium ions,the substituents Y^(j) on the same anion can be identical or different.They represent, independently of each other, H or one of thesubstituents indicated above for Y.

When M^(m+) is an organometallic cation, it can be chosen frommetalloceniums. For example, mention may be made of the cations derivedfrom ferrocene, from titanocene, from zirconocene, from an indocenium orfrom an arene metallocenium. It can also be chosen from metal cationscoordinated by atoms such as O, S, Se, N, P or As, borne by organicmolecules, in particular in the form of carbonyl, phosphine orporphyrine ligands optionally containing chirality. M^(m+) can also be acation derived from the alkyl groups defined for Y above and limited tothose containing from 1 to 10. carbon atoms, for example atrialkylsilyl, tetraalkylgermanyl or dialkylstannyl derivative; in thiscase, M is linked to the group [R¹—X¹(Z¹)—Q⁻—X²(Z²)—R²] via a verylabile covalent bond and the compound behaves like a salt. The cation M⁺can also be the repeating unit of a conjugate polymer in cationicoxidized form. As specific examples, mention may be made of themethylzinc, phenylmercury, trialkyltin or trialkyllead,chloro[ethylenebis(indenyl)]zirconium(IV) ortetrakis-(acetonitrile)palladium(II) cations. The organometallic cationcan form part of a polymer chain.

The compounds according to the invention in which at least one of thegroups X^(i) represents a phosphorous group are particularlyadvantageous for the great stability of the P—N and P—C bonds and fortheir flexibility. As a result, these compounds are more soluble andhave a lower melting point than the sulfur-containing homologouscompounds. Moreover, a large number of phosphorous compounds bearing twosubstituents R are commercially available or can readily be synthesized.For example, mention may be made of the compounds

Mention may be made in particular of the phosphorous compounds in whichQ represents N.

The compounds in which the radicals Z^(i) represent R_(F)SO₂N and thosein which the radicals R^(i) represent a perfluoro group or an alkylgroup are particularly advantageous, especially for the high acidity andthe dissociation of the corresponding salts.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Among the compounds of the present invention corresponding to formula(I), mention may be made of those in which the groups X^(i) representS—Z^(i), more particularly those in which Q is N, and which correspond,respectively, to the formulae:

One particular family of compounds according to the inventioncorresponds to formula (VII), given that if R¹ is CF₃, R₂ is a phenyloptionally bearing a halogen or an NO₂, three substituents Z^(i)represent O and one substituent Z^(i) represents ═NSO₂CF₃, then M isother than an alkali metal cation or a proton.

Another family of compounds according to the invention corresponds toformula (I) in which the radicals R¹ and R² are chosen, independently ofeach other, from perfluoroalkyl radicals preferably containing from 1 to8 carbon atoms, alkyl radicals preferably containing from 1 to 8 carbonatoms, alkenyl radicals preferably containing from 2 to 18 carbon atoms,dialkylamino radicals in which the alkyl radicals preferably containfrom 1 to 18 carbon atoms, and styrenyl radicals. For example, mentionmay be made of the compounds corresponding to the following formulae, inwhich R_(f) represents a perfluoro radical, Q and M have the meaninggiven above, and Y, Y′, Y″, Y′″ and Y″″ have the meaning given above forY:

The compounds corresponding to formula (I), in which the groups Z^(i)are chosen from ═O, ═N—C≡N and ═C(C≡N)₂, constitute another advantageousfamily. The presence of one or more groups ═N—C≡N or ═C(C≡N)₂, makes itpossible to increase the dissociation and the resistance to oxidation ofthe anion without substantially increasing its molar mass or its volume.For example, mention may be made of the following compounds:

Mention may also be made in particular of the compounds corresponding tothe formula (IV)

in which three groups Z¹ to Z³ represent oxygen and Z⁴ represents═C[S(═Z)₂R⁶]₂. For example, mention may be made of the followingcompounds:

Mention may also be made of the compounds corresponding to the formula

in which the groups R^(i), Z^(i) and Q have the meaning given above, inparticular compounds in which the groups Z^(i) are O, and Q is N.

Mention may also be made of the compounds of formula

in which the groups R_(f) and R′_(f) represent perfluoroalkyl radicals,the groups Z^(i) and R^(i) have the meaning given above, in particularcompounds in which the groups Z^(i) are O, and R_(f) is CF₃.

In general, the replacement of the oxygen in the SO₂ end groups of

with groups Z representing ═NSO₂R^(i) makes it possible to constructmolecules of general formula:

The choice of the substituents R^(i) in the compounds of the presentinvention makes it possible to obtain compounds in which the anion hasintrinsic chirality on a sulfur atom. Such compounds are useful forinducing enantiomeric selectivity during the preparation of activeorganic compounds or for inducing stereoselectivity in polymerizationreactions. Among these compounds, mention may be made of thosecorresponding to one or other of the following formulae[R¹SO₂N—S*═O(R²)═NSO₂R⁶]⁻ in which R¹ is different from R⁶, or[R¹SO₂N—S*═O(R²)═N—S*═O(R⁵)═NSO₂R⁶]⁻. The compounds most particularlypreferred are those in which R¹ and R⁶ represent, independently of eachother, a radical chosen from F, CF₃, C₂F₅, C₄F₉, C₆F₁₃ and C₈F₁₇, and R²and R⁵ represent, independently of each other, an alkyl, an aryl, analkylaryl or a dialkylamino preferably containing from 1 to 20 carbonatoms.

The ionic compounds of the present invention can be prepared by variousprocesses.

In general, a compound corresponding to the formula

is prepared by reacting a precursor compound, noted below (Z¹,L)comprising the group Z¹ and a leaving group L, with a derivative A²Z² ofthe group Z² according to one of the following reaction schemes:R¹—X¹(Z¹)—Q—X²(L)R²+A²Z²[R¹—X¹(Z¹)—X²(L)(Z2)R²]A⁺LAorR¹—X¹(Z¹)—QA₂+L—X²(Z²)R²[R¹—X¹(Z¹)—X²(L)(Z₂)R²]⁺A⁻+LA.

A represents an alkali metal, a proton, an amino orphosphorus-containing base, a trialkylsilyl group, a dialkylstannylgroup, MgL1, ZnL1, CdL1, Cu, Mg, Zn, Cd, Hg or a trialkylsilyl,trialkylgermanyl or trialkylstannyl group.

The leaving groups L or L1 are advantageously chosen from halogens,pseudohalogens including fluoro or non-fluoro sulfonates, and imidazoyl,triazolyl and benzotriazoyl radicals.

The compounds (Z¹,L) in which the leaving group is a halogen can beprepared, for example, by the action of a halogenating agent on a saltR¹—X¹(Z¹)—Q—X²(O)(R²)⁻A⁺ or on the corresponding acid. The cation A ispreferably chosen from alkali metal cations, inorganic ammonium ions NH₄⁺ or organic ammonium ions R³NH⁺ (including pyridinium) and the Ag⁺ ion,which has strong affinity for Cl, Br and I.

Among the halogenating agents which are useful, mention may be made ofSF₄, trifluoro(diethylamino)sulfur IV (DAST), thionyl chloride, oxalylchloride, oxalyl fluoride, phosphorus pentachloride, the mixturePΦ₃+CCl₄, (chloromethylene)dimethylammonium chloride[CH(Cl)═N(CH₃)₂]⁺Cl⁻ or its homologue derived fromN-methylpyrrolidinone, and 1-methyl-2-fluoropyridinium iodide. Thepreparation of a compound (Z¹,L) in which the leaving group is a halogenis illustrated schematically by the following example:[CF₃SO₂NSO₂(C₄H₉)]Na+(COCl)CO+CO₂+[CF₃SO₂NSO(C₄H₉)Cl]+NaCl

The precursor compounds (Z¹,L), in which the leaving group isimidazolyl, triazolyl or benzotriazolyl, can be obtained by the actionof their alkaline salt, their trimethylsilyl derivative or theirdimethylstannyl derivative on the corresponding halogenated precursorcompound, for example according to the following reaction scheme:[CF₃SO₂NSO(C₄H₉)]Cl]+ImSi(CH₃)₃ClSi(CH₃)₃+[CF₃SO₂NSO(C₄H₉)Im], in whichIm represents

The precursor compounds (Z¹,L), in which the leaving group is apseudohalogen such as a sulfonate, can be obtained by the action of theacid chloride or the anhydride of the sulfonic acid corresponding to thesulfonate, on an abovementioned salt R¹—X¹(Z¹)—Q—X²(O)R²⁻M⁺. Thereaction of a silver salt with a sulfonyl chloride R⁷SO²Cl (R⁷ being ofthe same nature as the groups R^(i)) according to the following schemeis particularly advantageous:R¹—X(Z¹)—Q—X(O)R²⁻Ag⁺+R⁷SO₂ClR¹—X(Z¹)—Q—X(SO₃R⁷)R²+AgCl

In general, it is advantageous to prepare the precursor compoundsR¹—X¹(Z¹)—Q—X²(L)R² from a compound comprising an anion in which thesulfur or the phosphorus are in the oxidation state IV and III,respectively. On oxidizing these anions, the sulfur VI or phosphorus Vderivatives are obtained according to the reaction schemeR¹—X(Z¹)—Q—X²(R²)⁻A⁺+2LR¹—X(Z¹)—Q—X²(L)R²+LA

The preferred compounds for L are halogens, such as fluorine, chlorineor bromine.

The various leaving groups can be exchanged by techniques that are wellknown to those skilled in the art. For example, the chlorine can bereplaced with fluorine by the action of an agent containing activefluoride ions and an affinity for the chlorine ions, such as silverfluoride AgF or tetramethylammonium fluoride,1,1,1,3,3,3-hexakis(dimethylamino)-diphosphazenium fluoride{[(CH₃)₂N]₃P)}₂N⁺F⁻ ortetrakis(tris(dimethylamino)-phosphoranylidene-aminophosphoniumfluoride{[(CH₃)₂N]₃P═N}₄P⁺F⁻ or the compound of addition oftris(dimethylamino)sulfonium fluoride with trimethylfluorosilane[(CH₃)₂N]₃S⁺[Si(CH₃)₃F₂]⁻.

The imidazole or triazole derivatives can be obtained by the action oftheir alkaline salt or their trimethylsilyl or dimethylstannylderivative) on the corresponding derivative, according to the reactionscheme:[CF₃SO₂NSO(C₄H₉)Cl]+ImSi(CH₃)₃ClSi(CH₃)₃+[CF₃SO₂NSO(C₄H₉)Im]in which Im represents imidazolyl, triazolyl or benzotriazolyl.

A symmetrical compound, in which X¹(Z¹) is identical to X²(Z²), can beprepared by the action of an ionic nitride or a metallic derivative ofhexamethyl-disilazane or of ammonia in the presence of a base on aprecursor containing a leaving group L, according to the followingreaction scheme, in which R, X and Z have the meaning given above,respectively, for R^(i), X^(i) and Z^(i), A and L are as defined above:2RX(Z)L+A₃N[RX(Z)]₂N⁻A⁺+2LA. For example:2CF₃SO(═NSO₂CF₃)F+Li₃N[CF₃SO(═NSO₂CF₃)]₂N⁻A⁺+2LiF

The nitriding agent may advantageously be Li₃N, ammonia, its derivativeswith silanes and their alkali metal derivatives such as N[SiCH₃)₃]₂Li,N[SiCH₃)₃]₂Na, and N[SiCH₃)₃]₂K.

A compound of formula [R¹SO₂N—S*═O(R²)═NSO₂R³]⁻M⁺ can be obtained byreacting a salt [R¹SO₂NSO₂R²]⁻M′⁺ with a halogenating agent, to give theprecursor R¹SO₂NSOR²(X) (X being a halogen). Said precursor is thencondensed with a sulfonamide R³SO₂NH₂ in the presence of a base or withits metallic derivatives such as R³SO₂NLi₂ or R³SO₂NNa₂. The desiredcation for the final compound is obtained by standard ion-exchangeprocesses.

In the same way, the ionic carbides allow the compounds [RX(Z)]₃C⁻A⁺ tobe prepared, according to the reaction scheme2RX(Z)L+A₄C[RX(Z)]₃C⁻A⁺+3LA.

Given the large possible choice for the substituents which can bepresent on the anionic group, the compounds of the invention make itpossible to induce ionic conduction properties in most organic, liquidor polymeric media containing polarity, even low polarity. Theapplications are important in the field of electrochemistry, inparticular for the storage of energy in primary or secondary generators,in supercapacitors, in fuel cells and in electroluminescent diodes. Thecompatibility of the ionic compounds of the invention with organicliquids or polymers makes it possible to induce pronounced antistaticproperties, even when the content of ionic compound is extremely low.Accordingly, another subject of the present invention consists of an ionconducting material consisting of an ionic compound of the presentinvention dissolved in a solvent.

The ionic compound used to produce an ion conducting material ispreferably chosen from compounds whose cation is ammonium, or a cationderived from a metal, in particular lithium or potassium, zinc, calcium,rare-earth metals, or an organic cation, such as a substituted ammonium,an imidazolium, a triazolium, a pyridinium or a4-dimethylaminopyridinium, said cations optionally bearing a substituenton the carbon atoms of the ring. The ion conducting material thusobtained has high conductivity and high solubility in solvents, onaccount of the weak interactions between the positive charge and thenegative charge. It has a broad field of electrochemical stability, andit is stable in both reducing and oxidizing media. Furthermore, thecompounds which have an organic cation and a melting point below 150°C., in particular the compounds containing an imidazolium, triazolium,pyridinium or 4-dimethylaminopyridinium cation, have high intrinsicconductivity, even in the absence of solvent, when they are in themolten state.

The solvent for an ion conducting material of the invention can be anaprotic liquid solvent, a solvating polymer, a polar polymer or amixture thereof. The aprotic liquid solvent is chosen, for example, fromlinear ethers and cyclic ethers, esters, nitriles, nitro derivatives,amides, sulfones, sulfolanes, alkylsulfamides and partially hydrogenatedhydrocarbons. The solvents which are particularly preferred are diethylether, dimethoxyethane, glyme, tetrahydrofuran, dioxane,dimethyltetrahydrofuran, methyl or ethyl formate, propylene or ethylenecarbonate, alkylcarbonates (in particular dimethylcarbonate,diethylcarbonate and methyl propyl carbonate), butyrolactones,acetonitrile, benzonitrile, nitromethane, nitrobenzene,dimethylformamide, diethylformamide, N-methylpyrrolidone, dimethylsulfone, tetramethylene sulfone, tetramethylene sulfone andtetraalkylsulfonamides containing from 5 to 10 carbon atoms.

The solvent for the ion conducting material can be a polar polymerchosen from solvating, crosslinked or non-crosslinked polymers, bearingor not bearing grafted ionic groups. A solvating polymer is a polymerwhich contains solvating units containing at least one hetero atomchosen from sulfur, oxygen, nitrogen and fluorine. As examples ofsolvating polymers, mention may be made of polyethers of linear, comb orblock structure, forming or not forming a network, based onpoly(ethylene oxide), or polymers containing the ethylene oxide orpropylene oxide or allyl glycidyl ether unit, polyphosphazenes,crosslinked networks based on polyethylene glycol crosslinked withisocyanates or networks obtained by polycondensation and bearing groupswhich allow the incorporation of crosslinkable groups. Mention may alsobe made of block copolymers in which certain blocks bear functions whichhave redox properties. Needless to say, the above list is not limiting,and any polymer with solvating properties can be used.

An ion conducting material of the present invention can simultaneouslycomprise an aprotic liquid solvent chosen from the aprotic liquidsolvents mentioned above and a polar polymeric solvent comprising unitscontaining at least one hetero atom chosen from sulfur, nitrogen, oxygenand fluorine. It can comprise, from 2 to 98% of liquid solvent. Asexamples of such a polar polymer, mention may be made of polymers mainlycontaining units derived from acrylonitrile, from vinylidene fluoride,from N-vinylpyrrolidone or from methyl methacrylate. These polymers canbear ionic groups. The proportion of aprotic liquid in the solvent canrange from 2% (corresponding to a plasticized solvent) to 98%(corresponding to a gelled solvent). An ion conducting material of thepresent invention can also contain a salt conventionally used in theprior art for the production of an ion conducting material. Among thesalts which can be used as a mixture with an ionic compound according tothe invention, the salt most particularly preferred is chosen fromperfluoroalkane sulfonates, bis(perfluoroalkylsulfonyl)imides,bis(perfluoroalkylsulfonyl)methanes andtris(perfluoroalkylsulfonyl)methanes.

Needless to say, an ion conducting material of the invention can alsocontain the additives conventionally used in this type of material, andin particular inorganic or organic fillers in powder or fibre form.

An ion conducting material of the invention can be used as anelectrolyte in an electrochemical generator. Another subject of thepresent invention is thus an electrochemical generator comprising anegative electrode and a positive electrode which are separated by anelectrolyte, characterized in that the electrolyte is an ion conductingmaterial as defined above. Preferably, the cation of the ionic compoundof the electrolyte is Li⁺ or K⁺. According to one specific embodiment,such a generator comprises a negative electrode consisting of lithiummetal, or an alloy thereof, optionally in the form of a manometricdispersion in lithium oxide, or a nitride double salt of lithium and ofa transition metal, or an oxide of low potential having the generalformula Li_(1+y)Ti_(2-x/4)O₄ (0≦x, y≦1), or carbon and carbon-basedproducts derived from the pyrolysis of organic materials. When thenegative electrode functions by exchanging lithium ions, it isparticularly advantageous to use, for the electrolyte, a compound of theinvention in which the cation is an Li⁺ ion. According to anotherembodiment, the generator comprises a positive electrode chosen fromvanadium oxides VO_(x) (2≦x≦2.5), LiV₃O₈, Li_(y)Ni_(1-x)Co_(x)O₂, (0≦x,y≦1), magnesium spinels Li_(y)Mn_(1-x)M_(x)O₂, (M═Cr, Al, V, Ni,0≦x≦0.5; 0≦y≦2), organic polydisulfides, FeS, FeS₂, iron sulfateFe₂(SO₄)₃, iron and lithium phosphates and phosphosilicates of olivinestructure, or their products of substitution of the iron with manganese,which are used alone or as mixtures. The positive electrode collector ispreferably made of aluminum.

An ionic compound of the present invention can also be used to induce anionic conductivity in media of low polarity, such as aliphatic andaromatic hydrocarbons and media which contain a large fraction thereof,polymers of relatively unpolar and/or hydrophobic nature, andsupercritical carbon dioxide.

An ion conducting material of the present invention can also be used ina supercapacitor. Another subject of the present invention is,consequently, a supercapacitor using at least one carbon electrode witha high specific surface, or an electrode containing redox polymer, inwhich the electrolyte is an ion conducting material as defined above.

The ionic compounds of the present invention can be used for dopingpolymers in order to improve their electron conduction. The polymersconcerned are essentially polyacetylenes, polyphenylenes, polypyrrols,polythiophenes, polyanilines and polyquinolines which are substituted orunsubstituted, as well as polymers in which the aromatic units areseparated by the vinylene unit —CH═CH—. The doping process consists inpartially oxidizing the polymer in order to create carbocations whosecharge is compensated by the anions in the compounds of the invention.This doping can be carried, out chemically or electrochemically,optionally simultaneously with the formation of the polymer. For thisspecific application, compounds of the invention bearing a highlydelocalized charge are preferably chosen, in particular the compounds inwhich Z is ═C(C≡N)₂═NSO₂R or ═C(SO₂R)₂, which impart thermal andmechanical stability properties. The polymers thus doped are anothersubject of the present invention.

In addition, an ion conducting material of the present invention can beused as an electrolyte in an electrochromic device. An electrochromicdevice in which the electrolyte is an ion conducting material accordingto the invention is another subject of the present invention. Such adevice also comprises electrodes whose active material is chosen fromWO₃, MoO₃, iridium oxyhydroxides IrO_(x)H_(y), (2≦x≦3; 0≦y≦3), Prussianblue, viologens and their polymers, and aromatic polyimides.

The compounds of the present invention can be used for the catalysis ofvarious types of chemical reaction, and in particular for polymerizationreactions, condensation reactions, addition or elimination reactions,oxidation or reduction reactions, solvolyses, Friedel-Crafts reactionsand Diels-Alder reactions. For these applications in catalysis, thecompounds will be chosen essentially as a function of the cationassociated with the anionic part.

For the catalysis of Diels-Alder reactions or Friedel-Crafts reactions,the cations of an alkali metal, of an alkaline-earth metal, of atransition metal or of a rare-earth metal are suitable. Compoundscontaining an H⁺, Li⁺, Mg⁺⁺, Ca⁺⁺, Cu⁺⁺, Zn⁺⁺, Al⁺⁺⁺, Fe⁺⁺ or Fe⁺⁺⁺cation are preferred.

The compounds of the invention in which the cation is an onium of thediazonium, sulfonium, iodonium or metallocenium type can be used ascationic polymerization initiators, in particular for polymerizing orcrosslinking vinyl ethers, epoxides, acetals and cyclic ethers,vinylamides, oxazolines, isobutylene, styrene or siloxanes. Under theaction of actinic radiation, such compounds generate the correspondingacidic form which is capable of initiating a cationic polymerizationreaction. A compound of the invention can be used as a photoinitiatoroptionally in the presence of a sensitizer, or of a radical initiatorwhich can be initiated thermally or by actinic radiation. The compoundsof the invention in the form of an amine salt can serve as initiatorsfor cationic polymerizations by heating to release the correspondingprotonic form. Similarly, if the cation is a salt of a cationic azocompound (for example as represented below), it can serve, by heating,as an initiator for radical polymerizations.

The present invention makes it possible to obtain compounds in which theanion has intrinsic chirality, which makes it possible to induceenantiomeric asymmetry during the use of said compounds as catalysts, toprepare stereoregular polymers and to give the materials containing theman optical rotation.

The present invention is explained in further detail by means of theexamples which follow, which describe the preparation and various usesof compounds of the invention. However, the invention is not limited tothese examples.

EXAMPLE 1

The compound of sulfur in the state IV [CF₃SO₂NS(O)CF₃]⁻Na⁺ was preparedaccording to one or other of the two possible reaction schemes:CF₃S—SCF₃+CF₃SO₂NCl₂CF₃SO₂NS(Cl)CF₃+CF₃SClCF₃SO₂NS(Cl)CF₃+NaOS(CH₃)₃[CF₃SO₂NS(O)CF₃]⁻Na⁺+ClSi(CH₃)  a)orCF₃SO₂NNa₂+CF₃SO₂Cl[CF₃SO₂NS(O)CF₃]⁻Na⁺+NaCl  b)

The halogenated compound CF₃SO₂NS(Cl)CF₃ was prepared by chloridation ofthe sodium salt [obtained via one of the routes a) or b)] in the absenceof solvent and converted into the fluoro derivative by the action ofN(CH₃)₄F in ether at −35° C.

2.67 g of the halogenated compound CF₃SO₂NS(F)CF₃ in 20 ml of THF werereacted with 170 mg of lithium nitride to give the salt:

EXAMPLE 2

15.6 g of butanesulfonyl chloride were dissolved in 100 ml of anhydrousacetonitrile to which were added 14.9 g of trifluoromethanesulfonamideand 20.4 g of 1,4-diazabicyclo-2,2,2-octane (DABCO). The mixture wasstirred for 4 hours at room temperature and the DABCO hydrochlorideformed was then removed by centrifugation and the solvent was evaporatedoff. The solid residue was taken up in 100 ml of a saturated solution ofKCl in water to which were added 15 ml of acetic acid. The precipitateof [C₄H₉SO₂NSO₂CF₃]⁻K⁺ was filtered off and purified by crystallizationfrom hot water.

9.22 g of the salt obtained above were dissolved in 50 ml of anhydrousacetonitrile, to which were added 2.6 ml of oxalyl chloride (COCl)₂ andthree drops of DMF acting as catalyst. After the evolution of gasceased, 4.4 g of trifluoromethanesulfonamide and 6.73 g of DABCO wereadded. After stirring at room temperature, the DABCO hydrochlorideformed was removed by centrifugation and the solution was poured into100 ml of water containing 15% by weight of KCl and 15 ml of aceticacid. The precipitate was separated out, washed with water andrecrystallized from ethanol. It corresponds to the formula:

The reaction scheme for the successive steps of the process is asfollows:[C₄H₉SO₂NSO₂CF₃]⁻K⁺+(COCl)₂KCl+C₄H₉SO(Cl)NSO₂CF₃C₄H₉SO(Cl)NSO₂CF₃+2N(C₂H₄)₃NN(C₂H₄)₃NHCl+[C₄H₉SO(NSO₂CF₃)NSO₂CF₃]⁻N(C₂H₄)₃NH⁺[C₄H₉SO(NSO₂CF₃)NSO₂CF₃]—N(C₂H₄)₃NH⁺+KClN(C₂H₄)₃NHCl+[C₄H₉SO(NSO₂CF₃)NSO₂CF₃]⁻K⁺.

EXAMPLE 3

5 g of the salt of Example 2 were treated with 1.17 g of lithiumtetrafluoroborate in isopropanol. The KBF₄ precipitate was filtered offand the lithium salt was obtained by evaporation of the solvent anddrying under vacuum at 60° C.

1 g of polyethylene oxide of mass 10⁶ was dissolved in 30 ml ofacetonitrile with 834 mg of the lithium salt. The solution wasevaporated in a PTFE ring so as to form a 200 μm film. This film isamorphous according to the differential calorimetry study, and has aconductivity of greater than 2.10⁻⁵ Scm⁻¹ at 25° C.

EXAMPLE 4

6 ml of a 10M solution of butyllithium in hexane were added to 8.97 g ofnonafluorobutanesulfonamide in 25 ml of ether at −25° C., followed byaddition of 4.13 g of bis(trifluoromethyl)trichlorophophorane P(CF₃)Cl₃.The lithium chloride was removed by filtration and the salt:

was purified by recrystallization from dioxane and treatment of thesolvate under vacuum at 80° C. This salt is soluble in relativelynon-polar solvents such as ethyl carbonate (dielectric constant of 2.8)to form a solution which has a conductivity of greater than 4.10⁻³ Scm⁻¹and an anodic oxidation stability of +5.5 V vs. Li°:Li⁺.

EXAMPLE 5

The compound [C₈H₁₇SO₂NSO₂CF₃]⁻K⁺ was prepared by a procedure similar tothat of Example 2, using octanesulfonyl chloride. 36.3 g of thiscompound were dissolved in anhydrous DMF and 13 g of(chloromethylene)dimethylammonium chloride [CH(Cl)═N(CH₃)₂]⁺Cl⁻ wereadded. A precipitate of KCl was formed and was removed by filtration.1.7 g of lithium nitride were added to the solution. After stirring for24 hours at room temperature, the reaction product was centrifuged andthe supernatant was poured into 200 ml of water saturated with potassiumchloride. The pasty precipitate was separated out after settling hadtaken place and was washed several times with water and then extractedwith 50 ml of an equivalent-volume mixture of diethoxy-2-ethane anddichloromethane. After evaporation of the solvent, a hydrophobic saltwas obtained, having the formula:

This compound, either in the initial form of the potassium salt, or inthe form of the lithium salt obtained by ion-exchange, has pronouncedsurfactant and lubricant properties, and it is soluble in solvents witha low dielectric constant, in particular in aromatic hydrocarbons. Inthese two forms, Li or K salt, the compound facilitates the extrusion ofhomo- and copolymers based on ethylene oxide for the preparation of ionconducting films, as well as for the preparation of composite electrodesin which the active material is an insertion compound which can be usedfor the manufacture of electrochemical generators.

EXAMPLE 6

253 g of polyaniline protonated in chloride form were suspended inacetonitrile and 6.7 g of the compound of Example 5 were added. Themixture was stirred for 24 hours and the polymer, in which the chlorideions were exchanged with the ion (CF₃SO₂NSOC₈H₁₇)₂N⁻, was washed withwater and with ethanol to remove the KCl, then dried. The conjugatepolymer in conductive doped form is soluble in solvents of low polaritysuch as xylenes, dichloroethane or chloroform. The conductivity of thepolymer is greater than 1 Scm⁻¹ and stable with respect to atmosphericagents, in particular moisture.

It has anticorrosion properties. It especially allows ferrous metals tobe protected against corrosion.

EXAMPLE 7

The ionic compound [CF₃SO₂NSO₂(3,5-C₆H₃(CF₃)₂]⁻K⁺ was prepared by amethod similar to that of Example 2, starting with3,5-bis(trifluoromethyl)benzenesulfonyl chloride andtrifluoromethanesulfonamide. 18.6 g of salt were treated with 7 g ofDAST (C₂H₅)₂NSF₃. The fluoro compound obtained:

was purified by distillation under vacuum. 4.27 g of this compound wereadded to 30 ml of anhydrous THF containing 670 mg of malonotrile and 18mg of lithium hydride. At the end of the reaction, observed by the endof the release of hydrogen, the reaction mixture was filtered and theTHF was evaporated off. The solid residue was taken up in water andfiltered off. 4.4 g of brucine sulfate in 50 ml of water were added andthe reaction mixture was stirred for 24 hours. After separation anddrying, 8 g of the precipitate formed were treated with a solution of1.6 g of a solution of sodium tetraphenylborate in 20 ml of anequivalent-volume, water/ethanol solution. After filtration, thesolution was dried to give the sodium salt of the anion, which isintrinsically chiral at its sulfur atom, resolved into an active isomerwith brucine:

The lithium, magnesium or rare-earth metal and yttrium salts of thisanion induce enantiomeric excesses of from 50 to 92% during thecatalysis of Diels-Alder reactions and aldol condensations. Acationic-polymerization catalyst was prepared by the action of acetylchloride in stoichiometric amount on the silver salt, which was itselfobtained by exchanging the sodium salt with silver toluene sulfonate inan isopropanol/toluene mixture. This catalyst induces a polymerizationof propylene oxide into an optically active polymer. In a similarmanner, methyl vinyl ether is polymerized into a water-insolublecrystalline isotactic macromolecule, in contrast with the polymersobtained with non-chiral cationic initiators. The compounds:

also have intrinsic chirality at the anionic centre, allowing thecatalysis of reactions favouring an enantiomer, the polymerizationsgiving polymers which are optically active or which exhibit tacticity.

EXAMPLE 8

The compound [(C₄H₉SO₂)₂N]Na was prepared according to the method ofRunge et al. (Chem. Ber. 88-4, 533 (1955)) and halogenated with thionylchloride in acetonitrile, the reaction being catalyzed by DMF. Thechloride C₄H₉SO₂NSO(Cl)C₄H₉ dissolved in THF was treated with ammonia soas to form the sulfimidosulfamide C₄H₉SO₂NSO(NH₂)C₄H₉. Equimolar amountsof the chloride and the amide were reacted in pyridine to form thepyridinium salt:

The salt of the rhodamine dye 6G of this anion was precipitated bysimple mixing in water of rhodamine 6G perchlorate and of the pyridiniumsalt. This salt has pronounced solubility in a large number of organicsolvents, in particular in monomers such as methyl methacrylate or(styrene, and this solubility is maintained during the polymerization ofthese monomers. The solid solutions thus formed are highly fluorescentand allow the preparation of solid lasers, as thin films or as fibres.

EXAMPLE 9

Bis(indenyl)zirconium dichloride was treated with the silver salt of thecompound of Example 6 to give the compound:

in which X⁻ is [CF₃SO₂NSOC₈H₁₇]₂N⁻.

This metallocene has excellent solubility in the usual polymerizationsolvents such as toluene or aliphatic hydrocarbons, and it showsappreciable activity for the polymerization of α-olefins, in particularfor ethylene and propylene.

EXAMPLE 10

0.14 g (4.12 mmol) of Li₃N and 0.04 g (0.33 mol) of4-dimethylaminopyridine as catalyst were added, under argon, to asolution of 2.43 g, (8.25 mmol) ofN-(trifluoromethylsulfonyl)phenylsulfonimidoyl fluoride preparedaccording to the method described by Garlyauskajte et al. (Tetrahedron,vol. 50, p. 6891, 1994) in 4 ml of anhydrous THF. The reaction mediumwas then refluxed for 24 hours. After cooling and evaporation of thesolvent under vacuum, the residue obtained was dissolved in 10 ml ofwater and the solution was filtered and then passed through an AmberliteIR-120 ion-exchange column (acidic form). 50% of potassium hydroxidesolution was added to this solution. The precipitate formed wasseparated out, recrystallized from water and then dried by azeotropicdistillation with benzene. The compound below was thus obtained:

The corresponding lithium salt was obtained by ionic exchange withlithium chloride in THF. Concentrated solutions of this lithium salt inether are activated for the catalysis of Diels-Alder reactions.

EXAMPLE 11

2.83 g (10 mmol) ofN-(trifluoromethylsulfonyl)trifluoromethylsulfonimidoyl fluoride,prepared according to the method described in Example 1, dissolved in 4ml of anhydrous THF were added to a solution of 174 mg of Li₃N (10 mmol)in 4 ml of anhydrous THF, followed by addition of 0.04 g (0.33 mmol) of4-dimethylaminopyridine as catalyst. The reaction mixture was thenstirred for 24 hours. After evaporation of the solvents under vacuum,the residue obtained was taken up in saturated KCl solution. Theprecipitate formed was separated out, recrystallized from water and thendried by azeotropic distillation with benzene. The compound below wasthus obtained:

According to the same process, starting with [C₄F₉SO₂NSOC₄F₉]⁻Na⁺, thecompound below was obtained:

EXAMPLE 12

22.44 g (200 mmol) of 1,4-diazabicyclo[2.2.2]octane (DABCO) dissolved in20 ml of anhydrous tetrahydrofuran at 0° C. were added to a solution, at0° C. and under argon, of 14.36 g (100 mmol) of sulfamoyl chloride(CH₃)₂NSO₂Cl (sold by Aldrich) and 14.91 g oftrifluoromethanesulfonamide CF₃SO₂NH₂(100 mmol), prepared according tothe procedure of Example 2, in 60 ml of anhydrous tetrahydrofuran. After2 hours at 0° C., the reaction was continued for 24 hours at roomtemperature. The DABCO hydrochloride precipitate was removed byfiltration on a sinter funnel of porosity No. 4. After evaporation ofthe tetrahydrofuran and drying, the product was dissolved in 25 ml ofethanol. 9.81 g (100 mmol) of potassium acetate CH₃COOK were then addedand the precipitate obtained was then recrystallized from refluxingethanol. After cooling, filtration and drying, the potassium salt(CH₃)₂NSO₂NKSO₂CF₃ was recovered. 50 mmol of this salt were dissolved in30 ml of THF and then treated with 50 mmol of oxalyl chloride. Aprecipitate of potassium chloride formed rapidly, and was removed byfiltration. 5 mmol of Li₃N were then added, under argon, to the(CH₃)₂NS(Cl)O═NSO₂CF₃ solution. After stirring for 72 hours, the solventwas evaporated off and the residue was recrystallized from a solutionsaturated with potassium chloride. The compound below was obtained:

According to the same process, the compound below was obtained byreplacing the sulfamoyl chloride with butanesulfonyl chloride:

EXAMPLE 13

20 mmol of the sodium salt of sulfonimide [(CH₃)₂NSO₂]₂NNa were treatedwith 20 mmol of thionyl chloride SOCl₂ in 10 ml of anhydrousacetonitrile. A precipitate of sodium chloride formed rapidly,concomitantly with formation of (CH₃)₂NSO(Cl)═NSO₂N (CH₃)₂. Afterstirring for one hour, 20 mmol of CF₃SO₂NNa₂, prepared beforehand bytreating trifluoromethanesulfonamide with sodium methoxide in methanol,were added under argon. After, stirring for 24 hours, the reactionmedium was filtered and the solvent was then evaporated off. Afterpassage through a cation-exchange column, the compound below wasobtained:

EXAMPLE 14

10 mmol of p-styrenesulfonamide, 0.04 g (0.33 mmol) ofdimethylaminopyridine as catalyst and then 0.1 mmol oftert-butylhydroxyquinone were added, under argon, to 10 mmol ofN-(trifluoromethylsulfonyl)trifluorosulfonimidoyl fluoride preparedaccording to the method described in Example 1, dissolved in 10 ml ofanhydrous pyridine. The reaction medium was then stirred for 24 hours at40° C. After evaporation of the pyridine under vacuum, the residueobtained was taken up in THF and then stirred for 24 hours in thepresence of an excess of potassium phosphate K₃PO₄. After filtration andevaporation of the solvent, the compound below was obtained:

EXAMPLE 15

According to a process similar to that of Example 14, and replacing thep-styrenesulfonamide with allylsulfonamide, the compound below wasobtained:

EXAMPLE 16

5 mmol of diphenyliodonium chloride (C₆H₅)₂ICl and 5 mmol of thepotassium salt [C₄H₉SO₂N═S(═O)(CF₃)]₂NK described in Example 12 werestirred together for 24 hours in water. By extracting the aqueous phasewith dichloromethane, and after evaporation of the dichloromethane anddrying, the compound below was recovered:

This salt makes it possible to initiate, under the effect of actinicradiation (light, γ-rays, electron beams), cationic polymerizationreactions or cationic crosslinking reactions of electron-rich monomers,in particular vinyl ethers, propenyl ethers, epoxides, isobutylene orN-vinylpyrrolidinone.

It is soluble in most common organic solvents (tetrahydrofuran,acetonitrile, dimethylformamide, ethyl acetate, glymes, toluene, etc.)and in aprotic solvating polymers such as polyethylene oxide. It is alsosoluble to more than 10% by weight in reactive solvents such astriethylene glycol divinyl ether or cyclohexanedimethanol divinyl ether,in contrast, for example, with the bis(trifluoromethanesulfonyl)imidesalt of diphenyliodonium.

The photoinitiating properties of this salt were tested by irradiating asolution of triethylene glycol divinyl ether, containing it at 1% byweight, with U.V. radiation at 254 nm, with a power of 1900 mW/cm².After irradiation for a few seconds, the reactive solvent set to asolid, this reaction being highly exothermic.

EXAMPLE 17

The allylsulfonimide of Example 15 was epoxidized by the magnesium saltof commercial peroxyphthalic acid to give the salt:

A solution of 100 ml of anhydrous tetrahydrofuran, 50 mmol of said saltand 6 mmol of allyl glycidyl ether were introduced into a Parr®-typechemical reactor. After purging the reactor with argon, 146 mmol ofethylene oxide and then 100 μl of a 10⁻² M solution of potassiumt-butoxide in THF were introduced using a valve. The polymerization wasthen carried out under argon by heating the reaction medium at 60° C.for 48 hours. After cooling, the solution was concentrated and thepolymer was then recovered by reprecipitation from ether. Afterfiltration and drying, the potassium cations of this polyelectrolytewere exchanged with lithium cations by passage through a cation-exchangecolumn. The polyelectrolyte below was thus obtained:

x:y:z being for example 6:50:200 on account of the higher reactivity ofethylene oxide. This polymer makes it possible to prepare polymericelectrolytes or gelled electrolytes containing fixed anions, the polymerfulfilling the double function of a matrix for obtaining the gel and ofa polyelectrolyte.

A gelled electrolyte 40 μm in thickness containing (by weight) 30% ofthe above polyelectrolyte, 35% of ethylene carbonate and 35% ofpropylene carbonate) was thus prepared, after crosslinking the allylfunctions by UV irradiation in the presence of1,2-diphenyl-1-keto-2,2-dimethoxyethane. This gel has good mechanicalproperties and a conductivity of greater than 10⁻³ S.cm⁻¹ at 30° C. Thecation-transport number in this electrolyte was estimated at 0.85.

An electrochemical generator was assembled using, as electrolyte, thegelled electrolyte described above. The anode material was a carbon coke(80% by volume) mixed with the copolymer (PANSDTFSI) of this example innon-crosslinked form as binder (20% by volume). The cathode material wasa composite material consisting of carbon black (6% by volume), LiCoNiO₂(75% by volume) and non-crosslinked copolymer (PANSDTFSI) (20% byvolume). This generator gave good cycling performance at 25° C. It waspossible to achieve 1000 charge/discharge cycles between 3 and 4.2 V,preserving a capacitance of greater than 80% of the capacitance at thefirst cycle. The generator has very good performance during a powerdemand on account of the use of fixed anions. The use of fixed anionsalso made it possible to improve the change in the interface resistance.

This family of polymers is of great practical interest for thedevelopment of electrochemical generators.

EXAMPLE 18

By ion-exchange in acetone between the potassium salt[C₄H₉SO₂N═S(═O)(CF₃)]₂NK described in Example 12 with3,3′-diethylthiatricarbocyanine iodide (which is an infrared dye of thecyanine family, sold by Aldrich), followed by a reprecipitation fromwater, and after filtration and drying, the compound below was obtained:

This salt is very soluble in relatively non-polar solvents such asdichloromethane or methylene chloride, as well as in relativelynon-polar polymer matrices, such as polymethyl methacrylate.

Moreover, a very pronounced decrease was observed in the aggregation ofthe cationic dyes with each other on account of the “plasticizing”nature of the di-2-ethylhexylamino groups. This decrease in aggregationis an advantage since the aggregation phenomenon entails a broadening ofthe optical absorption bands which can prejudice the operating accuracyof systems using dyes, in particular optical data storage disks.

EXAMPLE 19

100 mmol of trimethoxysilane were dissolved in tetrahydrofuran in athree-necked round-bottomed flask equipped with a condenser, amechanical stirrer and an inlet for neutral gas (Argon); 100 mmol of thepotassium salt described in Example 15 and 70 mg of chloroplatinic acidH₂PtCl₆ were then added. The mixture was refluxed for 4 hours. Aftercooling and evaporation of the THF, the compound below was obtained:

This compound was grafted to the surface of silica particles pretreatedin hydrochloric acid solution. Such silica particles are particularlyuseful for carrying out supported catalysis using a suitable cation.

EXAMPLE 20

10 mmol of the potassium salt [C₄F₉SO₂N═S(═O)(CF₃)]₂NK described inExample 11, were treated with silver tetrafluoroborate in an 80/20mixture of toluene dioxane. After stirring for a few hours, the reactionmedium was filtered to remove the potassium tetrafluoroborateprecipitate and anhydrous hydrogen chloride gas in toluene was thenbubbled through. After filtration to remove the silver chloride formed,and addition of silica particles, the solvent was evaporated off to givethe acid [C₄F₉SO₂N═S(═O)(CF₃)]₂NH deposited on silica. 1 mol of octaneand 10 mmol of acid supported on silica were introduced into a Parrreactor and the reactor was then maintained at 200° C for 10 min. Theoctane was then isomerized into isooctane.

The acid [C₄F₉SO₂N═S(═O)(CF₃)]₂NH deposited on silica and used asisomerization catalyst has an excellent level of use and is easy torecover on account of its low volatility and its oleophobic nature, i.e.its insolubility in aliphatic hydrocarbons.

The acid [C₄F₉SO₂N═S(═O)(CF₃)]₂NH dissolved in fluorinated solvents suchas Fluorinert® (sold by the company 3M) can also be used to carry outchemical reactions involving an acidic catalysis in a two-phase medium,the reaction products, which are insoluble in the fluorinated fluid,being recovered by simple separation after settling has taken place.

EXAMPLE 21

10 mmol of the potassium salt [C₄H₉SO₂N═S(═O)(CF₃)]₂NK, obtained inExample 12, were stirred in water in the presence of 11 mmol of1-ethyl-3-methyl-1H-imidazolium chloride (10% excess, sold by Aldrich).A liquid phase denser than water was obtained. This phase was recoveredby extraction with dichloromethane. After evaporation of thedichloromethane and drying of the liquid obtained under vacuum at 40°C., the molten salt below was recovered:

This molten salt has a conductivity of greater than 4.10⁻³ S.cm⁻¹ and afreezing point of less than −20° C. Its broad redox stability rangemakes it a particularly advantageous electrolyte for electrochemicalgenerators such as lithium batteries, supercapacitors, light modulationsystems and photovoltaic cells.

EXAMPLE 22

10 mmol of the potassium salt [(CH₃)₂NSO₂N═S(═O)(CF₃)]₂NK, prepared asin Example 12, were dissolved in 20 ml of THF and were treated with 10mmol of oxalyl chloride. A precipitate of potassium chloride formedrapidly and was removed by filtration. 5 mmol of Li₃N were then added,under argon, to the filtered solution. After stirring for 48 hours, thesolvent was evaporated off and the residue was recrystallized fromsaturated potassium chloride solution. The compound below was obtained:

1. Ionic compound corresponding to one of the formulae

in which: M^(m+) is a proton or a metal cation having the valency m,chosen from ions of alkali metals, of alkaline-earth metals, oftransition metals or of rare-earth metals, or an organic onium cation oran organometallic cation, 1≦m≦3; Z¹ and Z², denoted below by Z^(i),represent, independently of each other, O, NC≡N, C(C≡N)₂, NS(═Z)₂R⁶ orC[S(═Z)₂R⁶]₂, Z having the same meaning as Z^(i). R¹, R², R⁶ and R⁶′,denoted below by R^(i), represent, independently of each other, Y, YO—,YS—, Y₂N— or F; R_(f), and R_(f)′ represent a perfluoroalkyl radical; Yrepresents a monovalent organic radical chosen from alkyl, alkenyl,oxaalkyl, oxaalkenyl, azaalkyl, azaalkenyl, aryl, alkylaryl orperfluoroalkyl radicals, or from the radicals obtained from theabovementioned radicals by substitution, in the chains and/or thearomatic part, with hetero atoms chosen from halogens, oxygen, nitrogen,sulfur or phosphorus; with the proviso that if said heteroatoin issulfur or phosphorus, said sulfur or phosphorus atom can optionally bein the form of a —SO— group, a —SO₂ group or a >PO— group, oralternatively Y is a repeating unit of a polymeric backbone, wherein thecation M^(m+) is an organometallic cation chosen from metalloceniumions, metal cations coordinated by O, S, Se, N, P or As atoms and borneby organic molecules, trialkylsilyl, tetraalkylgermanyl ordialkylstannyl groups in which the alkyl radicals contain from 1 to 10carbon atoms, and wherein the organometallic cation forms part of apolymer chain.
 2. Ionic compound corresponding to one of the formulae

in which: M^(m+) is a proton or a metal cation having the valency m,chosen from ions of a alkali metals, of alkaline-earth metals, oftransition metals or of rare-earth metals, or an organic onium cation oran organometallic cation, 1≦m≦3; Z¹ and Z², denoted below by Z^(i),represent, independently of each other, O, NC≡N, C(C≡N)₂, NS(═Z)₂R⁶ orC[S(═Z)₂R⁶]₂, Z having the same meaning as Z^(i), R¹, R², R⁶ and R⁶′,denoted below by R^(i), represent, independently of each other, Y, YO—,YS—, Y₂N— or F; R_(f) and R_(f)′ represent a perfluoroalkyl radical; Yrepresents a monovalent organic radical chosen from alkyl, alkenyl,oxaalkyl, oxaalkenyl, azaalkyl, azaalkenyl, aryl, alkylaryl orperfluoroalkyl radicals, or from the radicals obtained from theabovementioned radicals by substitution, in the chains and/or thearomatic part, with hetero atoms chosen from halogens, oxygen, nitrogen,sulfur or phosphorus; with the proviso that if said heteroatom is sulfuror phosphorus, said sulfur or phosphorus atom can optionally be in theform of a —SO— group, a —SO² group or a >PO— group, or alternatively Yis a repeating unit of a polymeric backbone, wherein the cation M+ isthe repeating unit of a conjugate polymer in cationic oxidized form. 3.Ionic compound corresponding to the formula[R¹SO₂N—S*═O(R²)═NSO₂R⁶]_(m)M^(m+) in which: M^(m+)is a proton or ametal cation having the valency m, chosen from ions of at alkali metals,of alkaline-earth metals, of transition metals or of rare-earth metals,or an organic onium cation or an organometallic cation, 1≦m≦3; R¹, R²,and R⁶, denoted below by R^(i), represent, independently of each other,Y, YO—, YS—, Y₂N— or F; with the provision that R¹ is different from R⁶;Y represents a monovalent organic radical chosen from alkyl, alkenyl,oxaalkyl, oxaalkenyl, azaalkyl, azaalkenyl, aryl, alkylaryl orperfluoroalkyl radicals, or from the radicals obtained from theabovementioned radicals by substitution, in the chains and/or thearomatic part, with hetero atoms chosen from halogens, oxygen, nitrogen,sulfur or phosphorus; with the proviso that if said heteroatom is sulfuror phosphorus, said sulfur or phosphorus atom can optionally be in theform of a —SO— group, a —SO₂ group or a >PO— group, or alternatively Yis a repeating unit of a polymeric backbone, wherein the organometalliccation forms part of a polymer chain.
 4. Ionic compound corresponding tothe formula [R¹SO₂N—S*═O(R²)═NSO₂R⁶]_(m)M^(m+) in which: M^(m+)is aproton or a metal cation having the valency m, chosen from ions of atalkali metals, of alkaline-earth metals, of transition metals or ofrare-earth metals, or an organic onium cation or an organometalliccation, 1≦m≦3; R¹, R², and R⁶, denoted below by R^(i), represent,independently of each other, Y, YO—, YS—, Y₂N— or F; with the provisionthat R¹ is different from R⁶; Y represents a monovalent organic radicalchosen from alkyl, alkenyl, oxaalkyl, oxaalkenyl, azaalkyl, azaalkenyl,aryl, alkylaryl or perfluoroalkyl radicals, or from the radicalsobtained from the abovementioned radicals by substitution, in the chainsand/or the aromatic part, with hetero atoms chosen from halogens,oxygen, nitrogen, sulfur or phosphorus; with the proviso that if saidheteroatom is sulfur or phosphorus, said sulfur or phosphorus atom canoptionally be in the form of a —SO— group, a —SO₂ group or a >PO— group,or alternatively Y is a repeating unit of a polymeric backbone, whereinthe cation M⁺ is the repeating unit of a conjugate polymer in cationicoxidized form.